This invention relates to a buffer device for use in controlling the speed of motion of a controlled reciprocating member in either stroke, i.e. in either the forward stroke or the reverse stroke, by utilizing a damping mechanism such that a damping member is rotated within a sliding contact chamber.
As well known heretofore, there can be used various types of damping mechanisms for use in a "soft" ejecting device of cassette type tape recorders and cassette type video tape recorders, and these include the centrifugal force type, inertia type, friction type, oil type and air type. Among them a damping mechanism of the air governor type is the most insusceptible to changes in ambient conditions, the degree of machining accuracy of the parts and other requirements. In the damping mechanism of the air governor type, however, a vane wheel is rotated at a high speed so as to obtain a damping force, thus resulting in disadvantages such that the speed ratio becomes larger than in other types and, hence, the wheel or gear train and the vane wheel are apt to generate noise. Furthermore, the structure of the mechanism is increased in size and cannot be made thin, entailing another disadvantage such that the mechanism is not suitable for use in damping devices of small size. Since the damping force is proportional to the area of the vanes, the size of the device may not be arbitrarily reduced without a consequent reduction in damping ability. If a case for enclosing the air governor mechanism is used, the damping effect itself is reduced.
In case of friction type mechanism, when a speed increase is desired through a gear train, a high acceleration cannot be obtained, and if a strong force is applied, "cocking" may be caused.